1. Field of the Invention
The present invention relates to a locking device, and more particularly to locking device to secure an inner tube in an outer tube of a telescopic tube assembly.
2. Description of Related Art
With reference to FIG. 6, a conventional locking device (50) for a telescopic tube assembly having an outer tube (40) and an inner tube (41) slidably received in the outer tube (40) includes a knob (51) rotatably mounted on a side of the locking device (50).
When the relative position of the inner tube (41) is to be readjusted, the operator has to hold the inner tube (41) to prevent the inner tube (41) from slipping too far into the outer tube (40). Then the operator is able to unscrew the knob (51) and change the relative position of the inner tube (41) to the outer tube (40). However, when a distal end of the inner tube (41) is provided with a heavy load, i.e. an illuminating device, the operator has to struggle to hold the weight of the illuminating device. Therefore, assistance from the other operators is essential. That is, it is almost impossible for a lone operator to finish the adjustment of the telescopic tube assembly, especially when a weighty object is on top of the telescopic tube assembly.
To overcome the shortcomings, the present invention tends to provide an improved locking device to mitigate the aforementioned problems.